Permo-Carboniferous Ammonoids of the Glass Mountains 47 



not mean anything other than those rocks which yielded the rich fauna 

 described by J. G. Aguilera. 



Thus the data we possess at the present day do not furnish any proof 

 for the hypothesis that a marine communication existed from the Tor- 

 reon region toward the east, connecting the Trans-Pecos Permo-Car- 

 boniferous sea with that of the European Mediterranean. But neither 

 do they exckide the possibihty of the existence of such a waterway; 

 the ammonoids of our Trans-Pecos Permo-Carboniferous make it 

 evident that some kind of a marine communication must have existed 

 at least at the time of our zone of Waagenoceras. It does not seem 

 that this communication went through the northern states of the 

 Union, because the Permo-Carboniferous strata of those parts indicate 

 the existence of a shallow sea or even brackish water, while the fauna 

 of the Trans-Pecos beds must have lived in deeper water or at least 

 farther from a coast. Directly east from the Trans-Pecos region, no 

 fauna like that of our zone of Waagenoceras has been discovered so 

 far, but the zone of Perrinites seems to be well represented in the 

 middle part of the Double Mountain formation and in the Clear Fork 

 and Wichita-Albany beds. Unfortunately, Perrinites is known only in 

 Texas and even related forms have not been found anywhere else, if 

 we do not consider Perrinites as a form vicariating for Hyattoceras. 

 But the other fossils which accompany the former genus are very sim- 

 ilar to those found near Palermo in Sicily, and make it probable to a 

 certain degree that the Permo-Carboniferous of Central Texas was in 

 direct communication with the European Mediterranean. This com- 

 munication may not have existed in the northern part of the state, 

 but rather farther to the south ; because the character of the beds in 

 north Texas indicate very shallow littoral waters in the lower forma- 

 tions as well as in the upper, while to the south (Runnels and Cole- 

 man counties), at least the lower strata (Albany formation) have 

 the character of deposits in waters that were somewhat farther from 

 the coast. It may even be that the marine communication did not 

 exist in Texas at all, but in Northern Mexico. 



That a marine communication has existed also between the Trans- 

 Pecos and the Indian Permo-Carboniferous sea appears to be very 

 probable. There are no ammonoids known in the Salt Range strata 

 which seem to correspond to ours in age, but the brachiopod fauna es- 



